The long-term goal of this program of research is to develop improved methods for bringing about diet change and for stimulating good appetite in the elderly. A thorough understanding of basic mechanisms of food selection in older individuals is necessary to accomplish that goal. Studies are proposed in three basic areas. Preliminary studies suggest that compared to young subjects, elderly subjects show lower levels of food neophobia (reluctance to try novel foods or dislike for the taste of novel foods). The influence of age and olfactory loss on food neophobia will be studied. Two methods for overcoming neophobia will be compared in young and elderly subjects. They include the use of information about novel foods (e.g. "Try it, it tastes good.") to increase willingness to sample the foods and a comparison of the effectiveness of smelling, tasting and ingesting novel foods in producing increased liking due to exposure. These studies will also provide information on whether food neophobia is based on fear of bodily harm or on fear of an unpleasant taste experience. The hypothesis that there is a hormonal mechanism for differences in types of foods craved by young and elderly women will be tested. Results of a pilot study indicate that individuals on restricted diets are more likely to report a craving than are individuals on unrestricted diets. Since elderly subjects are particularly likely to have restricted diets, the effect on cravings of eating a nutritionally adequate but monotonous diet will be assessed. There is a decline in the incidence of acquired food aversions with age. Since there is large olfactory component to aversions, it has been suggested that age-related olfactory decline is the mechanism for the reduced incidence of food aversions in the elderly. In one study, the olfactory hypothesis will be evaluated against an alternative, that the difference in incidence is due to age-related cognitive changes. In a second, prospective study, the olfactory hypothesis will be examined in a study of acquired food aversions in cancer patients who are undergoing chemotherapy.